Method and apparatus for processing a thread on a draw-spin-winding machine

ABSTRACT

The cutting means and suction means are arranged above the detection means so as to, first, draw in the thread against the suction means and to, second, sever the thread while the free ends is then drawn into the suction means. Both the cutting means and the suction means are pneumatically activated in response to the detection of a disturbance in the thread path by the detecting means.

United States Patent 7 Wirz, I v f 541 'rnon AND APPARATUS FOR PROCESSING ON A DRAW- SPIN-WINDINGMACHINE [72] Inventor: Armin Wirz, Deitlikon, Switzerland [73] Assignee: Rieter Machine Works, Ltd., Winterthur, Svvitzerland [22] Filed: OcL'Zl, 1969 [2l] Appl. No: 870,522

[30] Foreign Application Priority Nov. 6, 1968 Switzerland ..-.....16659 68-- s2 U.S.Cl. .....242/36 s1 Int.Cl. ..-...B6sh63/00 [58] Field of Search I. ..242/36, 37, 38,18 AA, 19;

[56] References Cited UNITED STATES PATENTS 2,412,403 1'2/1946 Jackson et a]. ..57/34.5 2,696,036 12/1954 Wyers, Jr ...57/34.5 X

151 3,685,752 1 51 Aug. 22, 1972 2,990,603 7/1961 Keith ..28/7l.3 3,051,364- 8/1962; Barnes et 1.... ..s7/3'4.5 3,066,471 12/19 2 Scragg ..s7/34.s 3,370,800 2/1968 Haberkem.....' ..242/36 3,380,676 4/1968 Jenny ..242/19 3,438,188 4/1969 Boggs ..242/37 x FOREIGN PATENTS OR APPLICATIONS 686,728 5/1964 Canada ..242 37 397,499 2/1966 Switzerland ..242/36 Primary Examiner-Stanley N. 011166111 Attorney-Kenyon & Kenyon Reilly Carr & Kenyon 57 Y ABSTRACT The cutting means and suction means are arranged abovethe detection means so as to, first, draw in the thread against the suction means and to, second, sever the thread while, the free ends is then drawn into the suction means. Both the cutting means and the suction means are pneumatically activated in response to the Q detection of a disturbance in the thread path by the detecting means.

14 Claims, 6 Drawing Figures METHOD AND APPARATUS FOR PROCESSING A THREAD N ADRAW-SPIN-WINDING MACHINE This invention relates to a method and apparatus for processing a thread on a spin-draw-winding machine. More particularly, this invention relates to a method and apparatus for detecting and correcting thread defects in a thread processed on a spin-draw-winding machine.

Spin-draw-winding machines have been known in which a plurality of endless filaments after emerging from a spinneret change from a plastic state into a rigid state in a spinning cabinet. The filaments are then provided with a finish on a preparation roll, collected into a thread, strengthened by drawing in a drawing device and finally taken up into a package on a winding device.

I Such spin-draw-winding machines, as are known, operate at very high thread speeds. As a result thread breakage which usually occur in the drawing zone as'a rule and cause laps on the drawrolls, must be detected early because of the fast accumulation of large-quantities of material which can be eliminated only with considerable effort and prolonged downtime. The same holds true for laps forming on the winding'device.

Further, the thread cutting devices provided for cutting the thread and usually arranged upstream from the first drawroll as shown e.g., in Swiss Pat. No. 494,832 issued Sept. 30, 1970, have not performed satisfactorily on a spin-draw-winding machine. This is because, after cutting the thread upstream from the drawing arrangement, more thread keeps being supplied by the spinneret which supply cannot be stopped without much time and trouble due to the spinning pressure acting on the spinneret. Retrieval of the thread end for re-threading has also proven very difdraw-winding'machi'ne can be held in a predetermined position to permit easy pick-up and maintaining of the ficult. A decisive shortcoming develops, however, if

thread tension in the input thread is eliminated by cutting, which immediately causes either lapping on the thread transporting elements or interruption of the taking of the filaments from the spinning filaments. This results in inadmissible material accumulations in the spinning cabinet, clearing of which necessitates timeconsuming work. Furthermore, a conventional cutting device cannot effect a clean cut at the high operating speeds usually used on spin-draw-winding machines, as the time needed for the cutting process of conventional cutting devices is too long. As a result, a few outer filaments of the thread are cut first while the other filaments are still drawn through the cutting device. This results in an accumulation of the filaments already severed on the cutting device which impairs the cutting function.

Accordingly, it is an object of the invention to permit a simple picking up of a thread for severing in a spindraw-winding machine.

It is another object of the invention to maintain thread tension after severing of the thread to correct a disturbance in the thread path.

It is another object of the invention to sever a thread in a spin-draw-winding machine in a rapid manner to effect aclean cut.

It is another object of the invention to position a thread in a spin-draw-winding machine in a predetermined position for severing.

Briefly, the invention provides a method and apparatus in which'a thread being processed in a spinthread tension after severing of the thread if a disturbance occurs in the thread path.

The method is incorporated into the overall spindraw-winding process in which a plurality of endless filaments emerging from a spinning cabinet are combined into a thread, drawn and wound up. The method includes the step of detecting the occurrence of a disturbance in the thread path and, in response to the detection of disturbance, of drawing the thread into a predetermined position and severing the thread downstream of this position. At the same time, the thread is maintained under a tension sufficient to maintain the thread path at the prede'temrined position. The thread can be drawn into the predetermined position pneumatically and in such a case can be held under the same pneumatic pressure to insure the maintenance of the thread tension. Further, the thread, after being severed, can be pneumatically separated into the individual filaments by a vortex so that the thread tension is increased considerably.

The apparatus of the invention includes a detection means arranged at some point in the path of the thread, such as at the drawing device or at the winding device, to be activated by a disturbance in the thread path, a thread cutting means arranged upstream of the detection means with respect to the thread path, and a suction means upstream of and in close vicinity to the cutting means for drawing in the thread. The suction means is also set close to the thread path and with the cutting means is activated by the detection means.

Once a thread disturbance is detected, the suction means is activated to draw in the thread. The cutting means is then activated to sever the thread while the suction means then draws in the cut end of the thread to maintain the thread under tension. To this end, the cutting means is provided with a pneumatic force accumulator to permit the delay of the cutting action with respect to the activation of the suction means as well as to allow the build up of a pressure sufficient to effect a rapid cutting action. The thread can then be rethreaded after the disturbance has been corrected and the spindraw-winding process can be restarted.

These and other objects and advantages of the invention will become more apparent from the following detailed description and appended claims taken in conjunction with the accompanying drawings in which:

FIG. 1 schematically illustrates a spin-draw-winding machine utilizing the method and apparatus of the invention;

FIG. 2 illustrates a perspective view of a cutting means according to the invention,

FIG. 3 illustrates a cross-sectional view of a accumulator of the cutting means according to the invention;

FIG. 4 illustrates a cross-sectional view of a suction means according to the invention;

the filaments and a thread guide 4 which combines the filaments into a thread 2. The machine also includes a drawing device having a pair of rotatable delivery rolls 5 and a pair of draw rolls 6 which rotate faster than the delivery rolls 5 and which draw the thread 2 at the usual drawing ratio. In addition the thread 2 is passed through a stationary thread guide 7, a traversing device The time needed for building up the pressure in the v room 31 can be chosen by means of an exchangeable or 8 as is known, and a drive roll 9 and is wound up in a known manner onto a package 10.

The machine is further provided with a detection means 11, 12 each between the rolls of the delivery rolls 5 and draw rolls 6. Each detection means is activated in response to a lap formation on the rolls of the drawing device. A detection means can also be arranged near the free thread path and can be activated by a lack of thread tension.

A thread cutting means 13 is disposed upstream of the delivery rolls 5 adjacent the thread path for severing of the thread 2 in response to activation of the detection means 11, 12. In addition, a suction means 14 is disposed immediately upstream of the cutting means 13 closely adjacent to the thread path. The cutting means 13 and suction means 14 are connected in common to a duct 15 which is supplied with compressed air from a suitable source (not shown), An electromagnetic valve 16 is disposed in this duct 15 in order to control the flow of air from the duct 15 to the respective cutting means 13 and suction means 14. The valve 16 is activated either via an electrical connection 15 by an impulse from either of the detection means 11, 12 or manually.

Referring to FIG. 2, the cutting means 13 includes a pivotally arranged blade 17, the edge 18 of which rests on a plate 19. The plate 19 contains a stationary cutting edge 20 in the form of a U-shaped recess 21 enlarged somewhat towards the inside, through which recess 21 the thread 2 runs without touching in normal operation. The pivoting axis 22 of the blade 17 is arranged so that, in the cutting operation, the thread 2 is caught in the recess 21 and cannot, as in conventional cutting devices, escape to the outside, which occurs with increasing frequency as thread speeds increase. The blade 17 has a slot 23 through which a projection 24 (FIG. 3) of a piston rod 25 is inserted. The pivoting of the blade 17 is controlled by reciprocation of the piston rod 25 which is controlled by a piston 26 slidably arranged in a compressed air cylinder 27.

Referring to FIG. 3, in order to hold the blade 17 in an idle position in which thread 2 passes uninfluenced through recess 21, a hold means is provided. This hold means is constituted by a groove 28 in the piston rod 25 into which balls 30 are pressed by springs 29 acting radially towards the inside form all sides so as to hold the piston rod 25 in place and thus the blade 17. If valve 16 (FIG. 1) opens, activated by detection means 11 or 12, compressed air is supplied via duct 15 to cylinder 27 and after a certain, if very small, lapse of time, a relatively large room 31 in the cylinder 27 is filled with air and pressure is built up there. Once a certain pressure is reached, the spring force of the springs 29 is overcome and the balls 30 are pushed to the outside by the piston rod 25, whereupon the piston 26 is released and jerks to the right to effect movement of the blade 17 at high speed towards the stationary cutting edge 20.

adjustable throttle valve 32 (FIG I) inserted into the supply line upstream from the cylinder 27. From the illustration, it is evident that if the room 31, acting as an air regulator, were not provided, i.e., if cylinder wall 33 were arranged in the position 34 indicated with dashdotted lines, the desired delay of the start of the piston movement would not be achieved. Also, as the pressure in the initially very small room 31 would decrease rapidly at the start of the piston movement, the speed of the cutting movement would be lower.

Referring to FIGS. 4 and 5, the suction means 14 includes a suction tube 35 adjacent the thread path and a diffusor tube 36 into which the inner end of the suction tube 35' merges leaving an annular gap 37. Both the tubes 35, 36 are mounted in a suitable housing 48 so as to define a cylindrical room or chamber 38 which surrounds the inner end of the suction tube 35. This room 38 communicates via a pair of tangentially oriented ducts 39 to a circumferential manifold 49 in the housing 48 which connects with the duct 15. In this way, compressed air can be discharged into the room 38 from the air duct 15 and associated means so as to create a vortex therein as well as in the diffusor tube 36. For satisfactory performance, air flow cross-section areas must be chosen such that a sufficiently effective throttle point is formed which prevents a pressure drop in the supply duct 15 to the suction means 14, as sufiicient pressure would not otherwise build up in the room 31 of the cutting means 13.

In operation, if one of the detection means l1, 12 is activated, the electromagnetic valve 16 is actuated so as to open the duct 15 to the passage of compressed air to the cutting means 13 and suction means 14. A high speed air vortex is then generated at the inner end of the suction tube 35 by the air emerging tangentially from the ducts 39 and is discharged into the diffusor tube 36 while air is sucked in through the suction tube 35 according to the ejector principle. Owing to this suction air stream, the thread 2 is diverted from the straight thread path, (indicated with dash-dotted lines in FIG. 1), to or closely to the inlet opening of the suction tube 35. simultaneously, the pressure is built up in the room 31 of the cylinder 27 so that after a short lapse of time while the thread is drawn against the tube 35, the blade 17 is activated and severs the thread 2. As the free end of the thread is still being supplied from above, the end is sucked through suction tube 35 before it can escape from the vicinity of the inlet opening of the suction tube 35. The air vortex acting in the diffusor tube 36 separates the individual filaments 40 of the thread 2 so that the air force acting on the thread 2 and the thread tension in the suction means 14 are increased. This ensures the taking up of the thread still emerging from spinning cabinet 1 and prevents accumulation from occurring in the cabinet 1.

In order to rethread the thread by means of a threading air gun (not shown) the thread is taken over upstream from the suction tube 35 and re-threaded onto the thread transporting elements of the machine. After completion of the re-threading operation, the valve 16 is shut again either by hand or by resetting of the detection means 11, 12 into normal operating position. The pressure in the cylinder 27 escapes via suction means 14 and the blade 17 moves back into its initial position indicated in FIG. 2. The thread 2 now can be re-inserted into the recess 21, whereupon the whole system is ready for action again;

Referring to FIG. 6, the thread suction means 41 and the cutting means 42 can alternatively be arranged after the drawing device and the detection means 44 can be arranged at the drive roll 45 of the winding device. As the thread is traversed by the traversing thread guide 46its movement extending up to the stationary thread guide 47, the suction means 41 and cutting means 42 must be arranged above this guide 46. I,

this arrangement, aftercutting, the thread remains threaded in the drawing device. As a result, the thread tension is maintained so that no laps can form in the drawing device which laps would otherwise immediately occur without the suction means as thread tension would be missing. 7

What is claimed is:

1. In combination with a spin-draw-winding machine having a spinning cabinet for spinning a thread, a drawing device downstream of said cabinet for drawing the thread emerging from said cabinet and a winding device for winding of the drawn thread wherein the thread follows a thread path extending from said spinning cabinet through said drawing device to said winding device;

at least one detection means arranged near at least one of said drawing device and said winding device for detecting disturbances in the thread moving through said predetermined thread path,

a pneumatically operable thread cutting means upstream of said winding device for severing the thread in said thread path,

a suction means upstream of said cutting means having a tube disposed near said thread path for drawing in the severed thread after the thread has been severed by said cutting means, and

means connected to said cutting means and said suction means for delivering a flow of air in response to the detection of a disturbance in the thread detected by said detection means to said cutting means and said suction means to pneumatically actuate said suction means to draw the thread in said thread path to said tube and to pneumatically actuate said cutting means to sever the thread after drawing of the thread to said tube whereby the thread passing from said spinning cabinet to said tube is maintainedunder tension prior to and subsequent to severing thereof.

2. The combination as set forth in claim 1 wherein said latter means includes a duct connected in common to said cutting means and said suction for delivering a flowof compressed air thereto for activation thereof, and a valve in said duct connected to said detection means for controlling the flow of air through said duct to said cutting means and said suction means in response to the detection of adisturbance in a thread in the thread path.

- 3.'The combination as set forth in claim 2 wherein said cutting means includes a force accumulator connected to said duct to receive and accumulate air therefrom and to actuate said cutting means to sever a thread after a predetermined air pressure is obtained therein.

4. The combination as set forth in claim ,1 wherein said latter means includes a throttle valve connected to said cutting means for delaying the flow of air delivered to said cutting means to delay the actuation of said cutting means relative to said suction means.

5. The combination as set forth in claim 4 wherein said throttle valve is adjustable.

6. The combination as set forth in claim 2 wherein said cutting means includes a stationary plate having a cutting edge, a movable blade, a pneumatically activated piston for moving said blade relative to said edge, a hold means for maintaining said blade in an idle position spaced from said edge and a force accumulator for releasing said blade from said hold means to move said blade at high speed from said position towards said edge.

7. The combination as set forth in claim 6 wherein said force accumulator includes a room between said piston and said duct for regulating the air therein.

8. The combination as set forth in claim 7 wherein said room is disposed within a cylinder and said piston is slidably mounted in said cylinder.

9. The combination as set forth in claim 1 wherein said cutting means and said suction means are disposed upstream of said drawing device.

10. The combination as set forth in claim 1 wherein said winding device includes a traversing thread guide and said cutting means and said suction means are arranged upstream of said traversing thread guide.

' 1 1. The combination of a detection means for detecting disturbances in a thread moving through a predetermined thread P suction means upstream of said detection means having a tube adjacent said thread path for drawing in the thread;

pneumatically operable cutting means downstream of said suction means for severing the thread in said thread path and means connected to said cutting means and said suction means for delivering a flow of air in response to the detection of a disturbance in the thread detected by said detection means to said cutting means and said suction means to pneumatically actuate said suction means to draw the thread in said thread path to said tube and to pneumatically actuate said cutting means to sever the thread after drawing of the thread to said tube whereby the thread extending to said tube is held under tension prior to and subsequent to severing thereof.

12. The combination as set forth in claim 1 1 wherein said suction means includes a diffusor tube, a suction tube merging into said diffusor tube to define an annular gap therewith, said suction tube having an end adjacent the thread path, a housing mounting said tubes therein to define a room surrounding the inner end of said suction tube, and means connected to said room for discharging compressed air into said room and said difiusor tube to create a vortex therein.

13. In a method for processing thread comprising the steps of combining a plurality of endless filaments into a thread, drawing the thread, and subsequently winding the thread onto a package; the further steps of detectv ing the occurrence of disturbances in the thread moving through a predetermined thread path, drawing the thread into predetermined position upstream of the disturbance in response to the detection of the disturbance while maintaining tension in the thread up- 

1. In combination with a spin-draw-winding machine having a spinning cabinet for spinning a thread, a drawing device downstream of said cabinet for drawing the thread emerging from said cabinet and a winding device for winding of the drawn thread wherein the thread follows a thread path extending from said spinning cabinet through said drawing device to said winding device; at least one detection means arranged near at least one of said drawing device and said winding device for detecting disturbances in the thread moving through said predetermined thread path, a pneumatically operable thread cutting means upstream of said winding device for severing the thread in said thread path, a suction means upstream of said cutting means having a tube disposed near said thread path for drawing in the severed thread after the thread has been severed by said cutting means, and means connected to said cutting means and said suction means for delivering a flow of air in response to the detection of a disturbance in the thread detected by said detection means to said cutting means and said suction means to pneumatically actuate said suction means to draw the thread in said thread path to said tube and to pneumatically actuate said cutting means to sever the thread after drawing of the thread to said tube whereby the thread passing from said spinning cabinet to said tube is maintained under tension prior to and subsequent to severing thereof.
 2. The combination as set forth in claim 1 wherein said latter means includes a duct connected in common to said cutting means and said suction means for delivering a flow of compressed air thereto for actuation thereof; and a valve in said duct connected to said detection means for controlling the flow of air through said duct to said cutting means and said suction means in response to the detection of a disturbance in a thread in the thread path.
 3. The combination as set forth in claim 2 wherein said cutting means includes a force accumulator connected to said duct to receive and accumulate air therefrom and to actuate said cutting means to sever a thread after a predetermined air pressure is obtained therein.
 4. The combination as set forth in claim 1 wherein said latter means includes a throttle valve connected to said cutting means for delaying the flow of air delivered to said cutting means to delay the actuation of said cutting means relative to said suction means.
 5. The combination as set forth in claim 4 wherein said throttle valve is adjustable.
 6. The combination as set forth in claim 2 wherein said cutting means includes a stationary plate having a cutting edge, a movable blade, a pneumatically activated piston for moving said blade relative to said edge, a hold means for maintaining said blade in an idle position spaced from said edge and a force accumulator for releasing said blade from said hold means to move said blade at high speed from said position towards said edge.
 7. The combination as set forth in claim 6 wherein said force accumulator includes a room between said piston and said duct for regulating the air therein.
 8. The combination as set forth in claim 7 wherein said room is disposed within a cylinder and said piston is slidably mounted in said cylinder.
 9. The combination as set forth in claim 1 wherein said cutting means and said suction means are disposed upstream of said drawing device.
 10. The combination as set forth in claim 1 wherein said winding device includes a traversing thread guide and said cutting means and said suction means are arranged upstream of said traversing thread guide.
 11. The combination of a detection means for detecting disturbances in a thread moving through a predetermined thread path; suction means upstream of said detection means having a tube adjacent said thread path for drawing in the thread; pneumatically operable cutting means downstream of said suction means for severing the thread in said thread path; and means connected to said cutting means and said suction means for deliverinG a flow of air in response to the detection of a disturbance in the thread detected by said detection means to said cutting means and said suction means to pneumatically actuate said suction means to draw the thread in said thread path to said tube and to pneumatically actuate said cutting means to sever the thread after drawing of the thread to said tube whereby the thread extending to said tube is held under tension prior to and subsequent to severing thereof.
 12. The combination as set forth in claim 11 wherein said suction means includes a diffusor tube, a suction tube merging into said diffusor tube to define an annular gap therewith, said suction tube having an end adjacent the thread path, a housing mounting said tubes therein to define a room surrounding the inner end of said suction tube, and means connected to said room for discharging compressed air into said room and said diffusor tube to create a vortex therein.
 13. In a method for processing thread comprising the steps of combining a plurality of endless filaments into a thread, drawing the thread, and subsequently winding the thread onto a package; the further steps of detecting the occurrence of disturbances in the thread moving through a predetermined thread path, drawing the thread into predetermined position upstream of the disturbance in response to the detection of the disturbance while maintaining tension in the thread upstream of said position and immediately thereafter severing the thread downstream of said position in response to the detection of the disturbance while permitting the severed thread to be held under tension upstream of said position.
 14. A method as set forth in claim 13 including the steps of separating the severed thread end into the individual filaments and maintaining said separate filaments in a vortex of air. 